Touch panels, such as for example digitizers and analog resistive touch screens are known in the art. These touch panels typically include a conductive tensioned membrane defining a touch surface that is stretched tautly over and spaced from a conductive substrate. When a pointer is used to contact the tensioned membrane with sufficient activation force, the tensioned membrane deflects and contacts the conductive substrate thereby to make an electrical contact. Determining voltage changes induced by the electrical contact allows the position of pointer contact on the touch surface to be determined and a position signal corresponding to the position of pointer contact to be generated.
Touch panels of this nature are often used in conjunction with a display such as a liquid crystal display (“LCD”) panel. In such cases, the touch panel is disposed over the display with images presented by the display being visible through the touch panel. In this manner, the touch panel and display combination permits touch interaction with a displayed graphical interface. Examples of touch panel and display implementations include tablet personal computers (“PCs”) and personal digital assistants (“PDAs”). Although PCs and PDAs are widely accepted, as the touch panel is disposed over the display the visual quality of displayed images can be somewhat distorted.
When a user uses a pointer to provide touch input, the pointer is commonly held in the hand in the same manner as more traditional writing instruments, such as for example a pen, when used to write on paper. The fleshy part of the palm adjacent the little finger, if not also the forearm, is typically rested on the touch surface to provide stability. When this technique is used to provide touch input, the area of contact between the user's hand and the touch surface is detected as input, obscuring the actual pointer touch input. This condition is commonly referred to as “palm reject”. As will be appreciated, improvements in touch panels to obviate or mitigate the above disadvantages are desired.
It is therefore an object of the present invention to provide a novel touch panel and method of manufacturing the same.